1

Treatment of TBLisa Chen, MD

Curry International TB CenterPulmonary/Critical Care, UCSF

9/2016

Overview: Treatment of TB Principles and goals of treatment Current drugs, recommended regimens, and duration of TB treatment Adverse drug reactions and monitoring Management of treatment failure End of treatment

Natural History of TB (pre‐rx era)

Death 55%

Chronic spreader 18%

Cure 27%

Caution: not stable “cure”

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Treatment Goals

Microbiological goals of anti‐TB 

chemotherapy

Kill tubercle bacilli rapidly (early bactericidal effect)

Eliminate persistent bacilli to achieve durable cure, i.e. prevent relapse (sterilizing effect)

Prevent the emergence of drug resistance

General Principles of Therapy

Always treat with a multiple‐drug regimen

Never add a single drug to a failing regimen

Isoniazid, rifampin, and pyrazinamide are the basis of modern short‐course chemotherapy

Duration of treatment depends on the drugs used (the weaker the regimen, the longer the treatment)

Case 166 year old female from Laos seen after immigration, found to be PPD+ (13mm)

CXR report: Left apical nodular densities consistent w/ prior granulomatous disease, pleural thickening

No symptoms, otherwise healthy

PMD treats with INH for LTBI x9 months

Patient returns 1 year later with 2 months of cough, significant weight loss, and CXR reveals LUL infiltrate with small cavitary lesion

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Drug resistance is conferred by genetic mutations of M.tb

INH = 1 in 106

RIF = 1 in 108

EMB = 1 in 106

Strep = 1 in 106

INH + RIF = 1 in 1014

Frequency of Random Naturally Occurring Resistance Mutations

Mixed population (susceptible and resistant)

INH resistant bacilli

Emergence of INH resistant strain because of ineffective treatment (INH monotherapy)

Effective multi-drug therapy

Effect of Treatment on Bacillary Population

Weeks

Log

cfu

0 2 4 6 8 10 12 14 16 18 20 22 24

Development of Drug Resistance

1 2

3

Multiple Drugs vs. Monotherapy

I = INH resistant, R = RIF resistant, P = PZA resistant, E = EMB resistant

INH

IR

EP

RIFPZAEMB

INH II

I I

I

I

Reichman, L.B., Lungs at Work.1992.

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General Principles of Therapy

Always treat with a multiple‐drug regimen

Never add a single drug to a failing regimen

Isoniazid, rifampin, and pyrazinamide are the basis of modern short‐course chemotherapy

Duration of treatment depends on the drugs used (the weaker the regimen, the longer the treatment)

Development of Drug Resistance

I = INH resistant, R = RIF resistant, P = PZA resistant

Further acquired resistance after single drug added

II

I I

I

I

IR IRIR

IRIR

IR

IR

IR

IRIR IR

IRIR

IRP

III

I

II

I

II

I II

IIP

IRI

INHRIFINH

Reichman, L.B., Lungs at Work.1992.

Drug Resistant Mutants Selected by:

Non‐adherence

Malabsorption

Inadequate drug regimen

Remember: The higher the burden of disease, the greater the number of wild resistant mutants. 

Minimize Breaks in treatment, especially in the first 2 months of treatment.

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Treatment of TBOrganization and Supervision

Role of the health department

Patient‐centered care

Case management with DOT is the preferred treatment strategy (2016 ATS/CDC/IDSA guidelines)

DOT Consensus statement: Chaulk CP, et al. JAMA 1998;279:943

Outcomes of DOT studies 1966-1996

Treatment of TBProvider Responsibility

“…any public health program or private provider 

undertaking to treat a patient with TB is 

assuming a public health function that includes 

not only prescribing an appropriate regimen 

but also ensuring adherence to the regimen 

until treatment is completed.”

ATS/CDC/IDSA. AJRCCM 2003

Ensuring Completion of Therapy: Patient‐centered DOTPatient adherence Single most important factor in treatment failure Patient‐centered DOT is the international 

standard of careElements of a successful DOT program In clinic: supportive, welcoming atmosphere; 

incentives/enables such as sandwiches, food coupons, bus tokens, fast passes for transit system can help

In the field: dedicated outreach workers who are “at home” and comfortable in patients’ milieu

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First‐line TB Drugs and regimens

General Principles of Therapy

Always treat with a multiple‐drug regimen

Never add a single drug to a failing regimen

Isoniazid, rifampin, and pyrazinamide are the basis of modern short‐course chemotherapy

Duration of treatment depends on the drugs used (the weaker the regimen, the longer the treatment)

Antibiotic Treatment of TBBegan Only 67 Years AgoHome brew treatment: Wolf’s liver boiled in wine Flesh of a she‐ass with broth Smoke of dried cow dung Elephant’s blood Woman’s milk Mice boiled in salt and oil The King’s touch Bleeding, purging, collapsing lung Healing hymns “Rigveda” (India)

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Timeline of TB drugs

1955: Cycloserine; (begin triple therapy)

1854: First sanatorium for “fresh air and rest”

1944: Streptomycin

1952: INH

1946: PAS

1882: Koch discovers bacillus 1959: RIF

1961: EMB1962: PZA

2010

Anti‐TB Drugs in the United States

First-line Drugs Second-line Drugs Third-line Drugs*Isoniazid Linezolid** (Linezolid**)Rifampin Moxifloxacin* BedaquilineRifapentine Levofloxacin* ClofazamineRifabutin* Ethionimide Imipenem/cilastinEthambutol Cycloserine MeropenamPyrazinamide p-Aminosalicylic acid* High-dose INH

Amikacin*Amoxicillin/clavulanteCapreomycin (Streptomycin)

Not in U.S. Gatifloxacin DelaminidKanamycinProthionimde; Terizidone

* Not approved by the United States FDA for use in the treatment of TB** Linezolid currently classified as 3rd line, but used by many as 2nd line agent

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Fixed‐Dose Combination Preparations in U.S.

Rifamate

• Isoniazid (150 mg) + rifampin (300 mg)

Rifater

• Isoniazid (50 mg) + rifampin (120 mg) + pyrazinamide (300 mg)

Prevents patients from taking some but not all their medications

May reduce the likelihood of acquiring drug‐resistance

Case 2 50 year old male from the Philippines recently diagnosed with cough and night sweats x3 weeks

No prior TB rx, no known contact with active case

AFB smear+  

What drugs will you start?

ATS/CDC/IDSA Treatment Guidelines August 2016 (last version 2003!)

Nahid et al, CID 2016

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Treatment of TBStandard Regimen: 6 month short course

Isoniazid

Rifampin

PZA

Ethambutol

0 1 2 3 4 5 6

(can stop once known pan-sensitive)

Months

Initial Phase Continuation Phase

But what does each drug contribute to combination?

Case 2 50 year old male from the Philippines recently diagnosed with smear+  TB

Started on INH/RIF/PZA/EMB

Diffuse rash developed by day 7 and all drugs held.  Rash resolves after 3 days

Start serial rechallenge

Case 2Which drug would you start first and why?

1. INH because it is the best early bactercidal

2. Rifampin due to its excellent sterilizing

3. PZA  to help shorten the course of rx

4. EMB as least likely to cause a rash

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Treatment of TBAction of Anti‐TB Agents

Continuousgrowth

Dormant

Spurts ofgrowth

Acid inhibition

Low

High

Speed ofbacteriagrowth

INH (RIF, SM, EMB)

RIF PZA

Mitchison DA. Int J Tuberc Lung Dis 1998;2:10

• Bactericidal effect: (INH/FQ>>RIF/SM>E)Reverse disease process and stop transmission

• Sterilizing effect:(RIF/PZA)Prevent relapse

Clinical correlation

Activities of Antituberculosis Drugs 

Highest ++++ High +++ Intermediate ++ Low +

DrugEarly

bactericidal activity

Preventing drug

resistance

Sterilizing activity

Isoniazid ++++ +++ ++

Rifampicin ++ +++ ++++

Pyrazinamide + + +++

Streptomycin ++ ++ ++

Ethambutol ++ - +++ ++ +

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PZA: minimal impact on prevention of drug resistance

Drug resistance is more likely to occur when the large burden of organisms are rapidly replicating (i.e. cavitation)

Activity of PZA is limited to special environments (e.g. acidic intra‐cellular environment)

Therefore, PZA as companion drug to protect against development of resistance is limited (avoid use if only two‐drug combo)

Recommended RegimensATS/CDC/IDSA  CID 2016

Initial Continuation

Reg Drugs Interval/Dose Drugs Interval/Dose

1 INHRIFEMBPZA

7 days/wk for 56 doses (8 wk) or 5 days/wk for 40

doses (8 wk)

INH/RIF 7 days/wk for 126 doses (18 wk) or 5 days/wk for 90

doses (18 wk)Total range of doses 182-130

Preferred regimen for patients with newly diagnosed pulmonary TB

5 vs. 7 daily doses:• When DOT is used, drugs may be given 5 days per wk and

the necessary number of doses adjusted accordingly.• Although no studies compare 5 with 7 daily doses, extensive

experience indicates this would be an effective practice. DOT should be used when drugs are administered <7 days per wk.

Intermittent dosingATS/CDC/IDSA  CID 2016

Preferred once daily for intensive and continuation phases (Strong recommendation; moderate certainty in the evidence)

Alternate regimens acceptable in certain program/public health situations (require DOT)

• Non‐HIV, non‐cavitary, low‐risk for relapse: can consider 3x wk dosing

• Some public health programs successfully use 2x wkdosing – new guidelines suggest caution – one missed dose is equivalent to 1 per wk dosing (shown inferior)

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Relapse risk with intermittent 6 mo. dosing:200 events in 5,208 patients (32 studies), Chang, AJRCCM 2006

Daily IP & CP relapse rate 1.9%, • 6% for Cav+, C2m+

• 0.6% for Cav‐, C2m‐

Relapse relative risk (RR) with intermittent dose• Daily IP, 3x CP: 1.6‐fold

• Daily IP, 2x CP: 2.8‐fold

• Daily IP, 1x CP: 7.1

Recommended RegimensATS/CDC/IDSA  CID 2016

Initial Continuation Effective-ness

Reg Drugs Interval/Dose Drugs Interval/Dose

2 INHRIFEMBPZA

7 days/wk for 56 doses (8 wk) or 5 days/wk for 40

doses (8 wk)

INHRIF

3x wkly for 54 doses (18 wk)

3 INHRIFEMBPZA

3X wkly for 24 doses (8 wk)

INHRIF

3x wkly for 54 doses (18 wk)

4 INHRIFEMBPZA

7 days/wk for 14 doses then

twice weekly for 12 doses

INHRIF

Twice wkly for 36 doses(18 wk)

General Principles of Therapy

Always treat with a multiple‐drug regimen

Never add a single drug to a failing regimen

Isoniazid, rifampin, and pyrazinamide are the basis of modern short‐course chemotherapy

Duration of treatment depends on the drugs used (the weaker the regimen, the longer the treatment)

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Treatment of TuberculosisOptimum Duration

Study Regimen Relapse Rate (%)

BTA, 1982 2IRE/7IR 1.5

2IRZS/4IR 2.5

2IRZE/4IR 2.5

USPHS 21, 1990 2IR(E)/4IR 3.5

9IR(E) 2.8

Denver, 1990 .5IRZS/1.5I2R2Z2S2/4I2R2

1.6

I – isoniazid, R – rifampin, Z –pyrazinamide, E – ethambutol, S - streptomycin

Even with standard rx

Treatment of TuberculosisIncreased Risk of Relapse

2‐month culture positive status • 7 BMRC trials 

• USPHS trial in Poland

• TBTC Study 22 (2002)

Cavitary disease• TBTC Study 22 (2002)

• Hong Kong (2004)

TBTC. Lancet 2002;360:528

Treatment of TuberculosisStudy 22 – Risk of Relapse

Continuation of INH/RIF twice wkly

Culture + at 2 mos

Cavity Yes No

Yes 20.8% 4.7%

No 5.9% 1.7%

Continuation of INH/RPT once wkly

Culture + at 2 mos

Cavity Yes No

Yes 22.2% 9.1%

No 11.8% 1.9%

TBTC. Lancet 2002;360:5281004 HIV-negative patients, standard 4 drug initiation; TBTC. Lancet 2002

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Treatment of TuberculosisExtending Therapy – 9 mo total duration

Isoniazid

Rifampin

Pyrazinamide

Ethambutol

0 1 2* 3 4 5 6 7 8 9

months

Initial Continuation Phase*

*If cavitary disease and culture (+) at 2 mos.,extend continuation phase from 4 to 7 mos.

Treatment of TBDecreasing the Risk of Relapse:

Hong Kong silicotuberculosis trial• Extending the continuation phase from               4 to 6 months decreased relapse rate from     22 to 7% (p<0.025)

Hong Kong PZA trial• Extending the duration of PZA (2, 4, 6 mo) had no significant effect on relapse6IR4S + 2Z: 3% relapsed

6IR4S + 4Z: 5% relapsed

6IR4S + 6Z: 3% relapsed

TBTC Study 22: Proportion (%) relapse: Low Ideal Body Weight (IBW) at dx combined with cavitation and/or positive 2‐mo culture Khan, AJRCCM 2006

< 90% IBW

Neither One Two Total

Yes4/71

5.6%

16/109

15%

17/51

33%

37/231

16%

No3/251

1.2%

8/212

3.8%

11/60

18%

22/523

4.2%

Total7/322

2.2%

24/321

7.5%

28/111

25%

59/754

7.8%

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Treatment of TBExtending Therapy

Consider extending the continuation phase with cavitation or delayed culture conversion plus:

• HIV infection, particularly if advanced

• Other form of immunosuppression, diabetes, or significant tobacco hx

• Underweight (< 90% of IBW)

• High burden: extensive radiographic disease 

Case 3

40 yo homeless man, originally from Ethiopia, has fever and cough x 4 weeks and lost 15 lb

AFB smears: 4+

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Overview: Treatment of TB Principles and goals of treatment Current drugs used, recommended regimens, and duration of TB treatment Adverse drug reactions and monitoring Management of treatment failure End of treatment

Adverse Reactions

Between 8‐18% have drug regimens modified

Most common side effects:• Rash• Gastrointestinal intolerance• Liver toxicity• Peripheral neuropathy (INH)• Optic neuritis (EMB)–dose and duration dependent

• Gout, arthropathy (PZA)

Isoniazid (INH)Adverse Effects

Asymptomatic transaminitis• Up to 5X upper limit normal in 10‐20%

Clinical hepatitis• With INH alone approximately 0.6%; 2.7% with RIF

Peripheral neurotoxicity• Less than 0.2% unless predisposing factors

Central nervous system effects• Not well quantified

Lupus‐like reaction• Approximately 20% develop positive ANA; Lupus in less than 1%

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Rifampin (RIF)Adverse Effects Cutaneous reactions

• Pruritus with or without rash in up to 6%

Gastrointestinal reactions

• Variable incidence but usually mild

Flu‐like syndrome

• Occurs in 0.4‐0.7% receiving 600 mg twice weekly

Hepatoxicity

• Transient asymptomatic hyperbilirubinemia in 0.6%

• Clinical hepatitis uncommon, usually cholestatic

Immunological reactions

• <0.1% develop plts, anemia, renal failure

Ethambutol (EMB)Adverse Effects

Retrobulbar neuritis

• Less than 1% with dose of 15 mg/kg

• 18% with more than 30 mg/kg/day

Peripheral neuritis

• Rare

Cutaneous reactions

• Approximately 0.2‐0.7% require discontinuation of drug

Pyrazinamide (PZA)Adverse Effects Hepatotoxicity

• About 1% develop clinical hepatitis, can be severe

Gastrointestinal symptoms• Mild anorexia and nausea are common

Non‐gouty polyarthralgia• Up to 40% receiving daily PZA, not serious

Hyperuricemia• Asymptomatic ‐ expected effect• Acute gouty arthritis ‐ rare except if pre‐existing gout

Cutaneous reactions• Transient morbilliform rash, self‐limited• Photosensitive dermatitis

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GI Intolerance

Discern between transient vs. persistent

Transient: pill burden, indigestion –BIW=>TIW=>daily dosing

Persistent: anorexia, nausea, and fatigue may signify liver toxicity

If hepatotoxicity suspected, hold meds and obtain liver function tests (LFTs)

If LFTs are normal, restart meds and reassure

Liver toxicity

Most feared adverse reaction

INH, rifampin, and PZA can all cause liver injury

Warn patients to seek immediate attention if anorexia, nausea, emesis, abdominal discomfort, fatigue, (or jaundice develops – but this is late!)

4‐5 fold increased risk with hepatitis C

Prevention: avoidance of alcohol and monitoring LFTs if other drugs with potential liver toxicity are used

Drug Induced Liver Injury (DILI)

Transaminase levels elevated• ≥ 3X ULN with symptoms • ≥ 5X ULN without symptoms: 

Response to DILI• Stop hepatotoxic medications.• Evaluate for viral hepatitis, biliary disease, alcohol, other hepatotoxic drugs

• Consider “liver sparing” regimen if interruption would be detrimental (EMB/FQN/Injectable)

AJRCCM 2006; 174: 935‐952

•

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Drug Induced Liver Injury (DILI)

After ALT <2X ULN: restart RIF ± EMB (or add RIF to liver sparing regimen)

After 3‐7 days: check LFT and restart INH• If hepatitis recurs: stop the last drug added

If RIF and INH tolerated: consider not using PZA• Disadvantages: 9 month regimen• Continue careful monitoring

AJRCCM 2006; 174: 935‐952

Liver Toxicity: Order of Re-challenge Depends on CircumstancesPatterns of hepatitis

Hepatocellular (increased transaminases): can be caused by all three 1st line agents

Cholestasis (high Alk phos and bilirubin) is usually due to rifampin

INH hepatitis: often age‐dependent

PZA hepatitis: often age & dose‐dependent

Case 4

58 yo man from India, diabetic. TST negative. He lives with his son, daughter‐in‐law who is pregnant and 2 yograndson

He drinks heavily and has hepatitis C infecion.

Cough x 6 wks, seen by PMD (failed trial abx)

20

Drug-Induced Peripheral Neurotoxicity

Drugs: INH, ethionamide, cycloserine, linezolid, (EMB)More common in patients with

• Diabetes• Alcoholism• HIV infection• Pregnancy

Usually symmetrical ‐ tingling, prickling, burning

Pyridoxine to prevent: 25‐50 mg daily (if baseline neuropathy, some experts use 100 mg; caution as B6 alone can cause neuropathy as dose increases)

ISTC TB Training Modules 2009

Monitoring: Adverse Reactions

• Drugs are listed in order of relative likelihood of causing adverse reaction.

• INH/RIF and RIF/PZA appear to have synergistic effects in causing hepatitis

Adverse Reaction DrugsRash PZA, INH, RIF, EMB

Gastrointestinal intolerance

PZA, RIF

Liver toxicity PZA, INH, RIF

Peripheral neuropathy INH, (EMB)

Optic neuritis EMB

Gout PZA

Case 533 y.o. man with LTBI & DM

TST 16 mm 7 yrs ago

Developed diabetes mellitus

Started on INH with 25 mg pyridoxine

Had a seizure at home after 2 weeks

PCP thought cause was hypoglycemia

Repeat seizure 3 weeks later

Case: Randall Reves

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Case 533 y.o. with seizure x2

Case 533 y.o. on INH with brain mass

Seizures controlled with phenytoin

Tuberculoma removed at craniotomy

AFB stains negative 

HRZE started post‐op 

Are there drug interactions to consider?

IsoniazidDrug Interactions

Isoniazid ‐ Relatively potent inhibitor of several cytochrome P450 isozymes, but not CYP3A

Inhibitory activity of INH increases the serum concentrations of phenytoin (Dilantin ®), carbamazepine (Tegretol ®), and diazepam

Rifampin has opposite effect and outweighs inhibitory effect of INH

INH may increase toxicity to acetaminophen, valproate, serotonergic antidepressants, disulfiram, warfarin, and theophylline

22

RifamycinsDrug Interactions Rifamycins ‐ Induce various isozymes of the cytochrome P450 system resulting in a decrease in serum concentration of many drugs

Enzyme induction: Rifampin>rifapentine>rifabutin

Ex. Corticosteroids, oral contraceptives, oral hypoglycemic agents, oral anticoagulants, phenytoin, cimetidine, digitalis, antiretroviral agents, immunosuppressants

Ask patients to bring in all concurrent medications

Communicate with the primary care provider

Case 533 y.o. on INH tuberculoma

Anticipated reduction in phenytoin levels discussed with Neurology

Levetiracetam (Keppra) started

Phenytoin stopped 

No further seizures during treatment  

Case 6

30 yo woman moved to US from India 4 yrs ago

Needs clearance to work in school

TST 12 mm 

No symptoms

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Case 6 

Now what?

Approach to the Patient: Culture Negative TB

CDC clinical diagnosis criteria (all required)

Clinical presentation consistent with TB

Clinical or radiographic response to anti‐TB therapy in the absence of another diagnosis

Positive TB skin test

Provider diagnosis

Selected cases reported without all 3 criteria above (e.g TST negative)18% of cases in U.S. are culture negative (CDC 2005)

*Again, clinical acumen and index of suspicion remain key

Treatment of Culture‐negative TB

TB suspect/PPD+Abnormal CXRSmear neg x3

High suspectRx: I/R/P/E

Low suspectNo rx

Months: 0 1 2 3 4 6 11

At 2 mo the cultures are negative

CXR unchanged = TB4

(INH)/RIF x 4 mo

INH x 9 mo

CXR / sx improved = Culture neg. case TBINH/RIF x 2 more mo**

CXR unchanged = TB4 Treatment done

**Guidelines, but ….

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Case 7

25 year asymptomatic Chinese woman who came to SF to attend college

PMH ‐ unremarkable

Habits ‐ 5 pack‐year smoker

Meds ‐ None

TST ‐ “positive” What would you do next?

Case 7

Case 7

Three sputum specimens were collected and noted to be AFB smear negative

A CT was performed:

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Case 6

Based on the mass‐like lesion on the CT, a bronchoscopy was performed. 

Bronchoalveolar lavage was AFB smear negative, cytology negative

What would you do now?

She grew M. tuberculosis from one of her sputum specimens!

Approach to the Patient: The Case for Presumptive Treatment

Earlier treatment may prevent the progression of disease and limit transmission

Presumptive treatment with standard RIPE x2 mo would fulfill current recommendation for LTBI (if turns out to not be active TB)

Adverse reaction in <10% of patients without active TB who were presumptively treated

Use rapid diagnostic tests to assist decision-making

Treatment of TuberculosisSpecial Situations

Pregnancy

Liver Disease

Renal Disease

HIV/Immunosuppressed

Pediatrics

Drug Resistant Disease

Extrapulmonary

To be discussed by others

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Routine Monitoring and FrequencySigns and symptoms Monitoring  Frequency

Sputum conversion Baseline, monthly till negative

Weight Monthly

LFTs Baseline, 1 month and prn

Side effectsMonthly: includes visual acuity and red/green discrimination, GI complaints, check for jaundice

Adherence and psychosocial issues affecting treatment

Weekly for DOT patients

MD evaluationsMinimum at baseline, 3 months and end of therapy 

Management of Relapse, Treatment Failure

90‐95% of patients treated for pulmonary TB will have negative sputum cultures by 3 months

If still culture positive after 3 months of therapy:

• Re‐check drug susceptibility tests

• Assess adherence

• Consider malabsorption of drugs

Management of Relapse, Treatment Failure (2)Treatment failure: Culture positive after 4 months of therapy

• Obtain rapid molecular DST

• If the patient is seriously ill or sputum AFB smear +, an empiric expanded regimen should be started with at least two new drugs

• If the patient is not seriously ill, consider waiting for the results of drug susceptibility testing 

• If malabsorption suspected, consider IV therapy (INH, rifampin, moxifloxacin) and check therapeutic drug levels

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Case 2 (continued saga) 50 year old male from the Philippines recently diagnosed with smear+  TB

Rash after 7 days INH/RIF/PZA/EMB

Serial restart (q2‐3 days) points to INH as source of rash

What would you treat with?

Alternate RegimensDrug Resistance (or intolerance) Without INH 

• 6‐9 month regimen of Rif, PZA, and EMB (+/‐FQ)• 9‐12 months Rif, EMB, FQ

Without Rifampin • 12‐18 month regimen of INH, EMB, and FQ (with PZA x2 mo)

• 18 month regimen of INH, EMB, PZA• If cavitary/extensive – or to support shorter 12 mo. duration, can add injectable for at least  first 2 mo

Without PZA• 9 months of INH/RIF (initial use of EMB while await DST)

Case 2 (continued saga) 50 year old male from the Philippines recently diagnosed with smear+  TB

Rash after 7 days INH/RIF/PZA/EMB

Serial restart points to INH as source of rash

What if  rash was due to RIF and he was INH resistant, is PZA/EMB a good idea?

No, PZA poor at preventing resistance

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Treatment of TBCompletion of Therapy

Initial phase: all of the specified doses should be delivered within 3 months

Continuation phase: all of the specified doses should be administered within 6 months

Thus, a 6‐month regimen should be completed within 9 months

End of Therapy

Determined by number of doses completed and not number of months

Duration of treatment is a clinical decision based on the following factors:‐ Extent of disease

‐ Time to sputum culture conversion

‐ Complexity of the case and site of disease

‐ Presence of drug resistance

End of treatment evaluation: chest x‐ray (CXR) and sputum (especially if adherence questionable or drug resistance found)

Treatment Outcomes for Pulmonary TB

98%64%

32%

20%18%

50%

10%

Dead

Sputum negative

Sputum positive

No Chemotherapy

PoorChemotherapy

Good Chemotherapy

0.8%

1.2%

Grzybowski S et al, Bull Int Union Tuberc 1978; (53)2: 70-5

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SummaryTreatment and its completion is the single most important factor in controlling TB in a population

• Cuts the line of transmission

• Decreases morbidity and mortality

• Prevents acquired drug resistance

Success requires provider knowledge, a patient‐centered approach, and a meaningful relationship between the patient and provider.

Use an expert when encountering problems!The End